Drawing sheet glass



June 3, 1930. c. A. RowLEY DRAWING SHEET GLASS Filed J'an. 25, 1924 2 Sheets-Sheet 2 |NvENT`oR WM Patented Jane 3, 193% UNrrn STATES i PATEn orricr.

CLIFFORD A. ROWLEY, OF TOLEDO, OHIO, .ASSIGNOR TO LBBEY-OWENS OIF-TOLEDO, OHIOJ A CORPORATION 0F OHIO enass COMPANY,

DRAWING strani" GLASS Application filed January 25, 1924. Serial No. 6885358.`

This invention yrelates to improvements in the art oi drawing sheet glass, and more particularly to an improved process and `apparatus for simultaneously and independently drawing a plurality ofsheets of glass.

1n the patent to Colburn 1,248,809, granted December 4, 1917, is disclosed a process and apparatus for drawing a single glass sheet. The sheet is drawn upwardly from a pool of molten glass, bent while still plastic about a cooled bending roller, and then carried horizontally over a moving drawing and flattening table, after which it passes horizontally through a long leer to a cutting tableV where it is divided into suitable sheet sections. By using the principles of the present invention this process is so modified that two or more sheets may be simultaneously but independently produced from thesame tank' and through the same drawing machine and leer.

The separate sheets are drawn vertically in spaced parallel planes from the same pool or" molten glass, each sheet'is bent into the horizontal about its own bending roller, and the sheets are passed horizontally in spaced parallel planes through the same leer from which each sheet emerges onto its own cutting table. The most diilicult problem to be solved in designing this new apparatus is to provide a drawing and flattening meohanism that can be installed in the necessarily narrow space between the parallelhorizontally travelingl sheets. This has been accomplished principally by making three changes from the formof drawing mechanism previously used; lirst, shorter links are used Jfor the flexible moving flattening table orbelt upon which the sheet is carried; second, a

simpler and. more compact drawing mecha nism above the sheet for holding the sheet in frictional Contact with the flattening table has been adopted; and third, the separate drawing mechanisms are arranged in staggered vertical relation so that therupper drawing mechanism for the lower sheet and the lower sheet-supporting drawing mechanism lfor the vupper sheet may be arranged in substantialhorizontal alignment, whereby the space between the superposed sheets need be no greater' than necessary for either one of the two mechanisms. i

The objects and advantages of this inven-` tion will be more apparent from the 'following detailed description of certain approved forms of mechanism designed according to the principles of this invention.

in the accompanying drawings:

Fig. 1 is a longitudinal vertical section through the sheet-forming portion of this apparatus and the entrance end ot the leer.

Fig. 2 is a similar view through the exit end of the leer, indicating the cutting tables for the diierent sheets. VIt is to be understood that a considerable portion of the leer has been omitted between the left-hand end f of Fig. l and the right-hand end of Fig. 2.

Fig. 3 is a plan view of a fragment of the sheet-supporting draw-table.

Figs. l and 5 are Views illustrating somewhat dilerent arrangements of the bending rollers.

It will be understood that the drawings here used are largely diagrammatic, and in detail the mechanism will he much the same as shown in the Colburn patent referred to above. At 1 is shown the draw-pot or receptacle containing the shallow pool of molten glass 2 from which the glass sheets are drawn. This pool 2 is in open communication with a continuous tank furnace wherein the molten glass is produced and from which the supply of glass in the pool 2 is replenished.

One of the glass sheets such as 3 is drawn upwardly from the pool 2 between pairs of edge-forming rollers 4 and coolers 5, all as described in detail in the Colburn patent.

The sheet is bent into the horizontal plane of the belt or chain is supported upon a stationary table 1d haring an upper flat horizontal surface.

In the flattening tabl-e heretofore in use, the

links 10 are about sii; inches in length, with four inches between pivot centers. lt has been discovered that by oecreasing the length ot' these links so that the distance between pivot centers is not over two, or two and onehal'l' inches, the 'chain is rendered much more fieilible and may be passed about smaller sprockets 12 and 13 at the ends olS the loop. By employing a plurality of' idler supper 'ing drums 15 for the lowerreturn run of the loop, and decreasing the vertical height or' the stationary supporting table 14, the overall Vertical height of the drawing and flattening table is made no greater than the necessary turning diameter at the ends ol' the loop, in the form described being less teau ten inches over all.. his is approximately the distance between eacn pair or glass sheets as they are passed horizontally through the drawing inachines and the leer. The draw-table using' the shorter ts 10 has the saine rea ot sheetsupporting surface as the table heretofore in use with longer links, and this area is better distributed, the holes 16 which represent unsupp `cd portions o'f the sheet being' smaller than in the older form.

Instead oi the endless loop ot draw-bars above the sheet for holding the sheet in fri-etional engagement with .the draw-table, as disclosed in the prior Colburn patent, a single roller 17, or preferably a pair of these rollers bearing upon the edge portions only or the sheet, is now usiil. lt has been demonstrated that these rollers, which are preferably driven, are amply sufficient to provide the necessary iirictional drawing' contact between the glass sheet and the surface of the sheet-suppontingg and flattening table.

The second glass sheet 18 is drawn upw rdly in a separate vertical plane parallel to the irst sheet 3 trom the same pool of molten glass 2, and bent around a cooled bending roller 19 similar to bending roll 6, but positioned somewhat lower than roll (i, so that the sheet 18 in che horizontal plane will pass just below the bot-tom of the lower return loop of draw-table 9 which supports and draws the upper sheet As stated above, the distance between the two sheets 3 and 18 inthe 'construction here shown will be approximately 1() inches. By suitably controlling the temperature condi. "ons around the separate sheets 3 and 18, each of these sheets may successfully be drawn, although there is the small. difference noted in the height of their vertical runs. The drawi: i' and flattening table 2O for the lower sheet 13 may be made ot exactlyv the same form as table 9 used Lt'or the upper sheet. Since the sheet 18 is drawn upwardly in a plane spaced to the left of that of sheet 3, the bending roll 19 and the intermediate supporting rollers will also be spaced to the left of the corresponding rollers used with sheet 3. For the reason the right-hand end of the lower `flattening table 2O will not project as far to the right as that of the upper table 9, and the lett-hand end of the lower table will project out beneadi and beyond the left-hand end oi the table 9. Preferably the lower table 20 is made somewhat longer'than the u table 9 so that a suilicient port-ion o1" the lat horizontal run ot this table 20 extends beyond the upper table 9 to allow the drawing rollers 17 for the lower sheet to rest thereon. It will lie noted that these drawing rollers 17 for the lower sheet are in substantial horizontal alignment with the drawing and supporting` table 9 'for the upper sheet, so that the distance between sheets 3 and 18 need be no greater than that required torthe loop table 9.

After leaving the drawing and flattening mechanism, each of the sheets 3 and 18 is passed independently 'through the leer 21 over its own system of driven supporting rollers 22. .A shield or screen 23 is preferably interposed between the upper conveyor rollers 22 and the lower sheet 18 to protect the lower sheet from breakage which might be caused by broken glass or other material falling `from the upper conveyor. Preferably, this screen 23 ywill be of some mesh construction which will not impede the passage of air currents, thus maintaining eren temperature conditions around both sheets.

At the exit end of the leer the upper sheet 3 passes out onto a cutting'ta ble, here shown as comprising aI series of spaced wooden sheet-supporting rollers 241. On this table tliercontinuous strip or ribbon of glass 3 may be divided into suitable sections such as 25. The conveyor yfor the lower sheet 18 extends under the cutting table 24, so that this sheet may be carried onto its own cutting table 26, which may be similar in every Way tothe table 24 already t escribed.

In Fig. 4 is illustrated a slight modification, wherein the bending rollers 6 and 19 are arranged ati-.the same Vertical height above the molten glass 2. Inthis case sheet 3 is bent upwardly at an angle from bending roll G and bent again through a small angle into the horizontal about vthe intermediate roller 7. The lower sheet 18, after passing over its bending roller 19, is allowed to droop downwardly as is shown at 27 before it passes over the intermediate supporting rolls onto the lower table 20.

. A slightly different modification shown in Fig. 5. In this case the sheet 3 is drawn in the same manner as in Fig. 1, but the bending roll 19 for lower sheet 1131's arranged somewhat higher than in Fig. 1. and sheet 1S is allowed to droop downwardly as at before it passes onto its iattening table 20.

The many advantages of this improved form of sheet-producing apparatus will be ini apparent. The production is doubled with only slight increases in the size and cost of the apparatus used. Although the parts used in the drawing machine are multiplied to some extent. the machine will be much less expensive than two single machines. The capacity oi the tank which supplies the molten glass will have to be increased but this tank will not be twice as large o1' expensive as a tank used for supplying glass to a single sheet machine. Only one leer is necessary for the two sheets. There will be only one tank, machine, and leer to heat, and the heating cost will only be slightly greater than that for a single sheet apparatus. The ifa-ctory room for this installation need be no wider, and only a few feet longer than the room required for a single sheet machine. In most instances the labor necessary for the single machine will suiiice for the double machine here disclosed.

While this apparatus has been described and shown as drawing two sheets of glass, it will be apparent that the apparatus might be modified to draw three or more sheets.

Claims:

l. In an apparatus 'for simultaneously drawing a plurality of sheets of glass, a container for a pool of molten glass, a plurality ot bending' members, one for each sheet, a

pluralityoir horizontal drawing and flattening tables, a roller above each table and the sheet carried thereby for holding the sheet in engagement with the table, the tables being l staggered so that the roller for a lower sheet may be positioned in substantial horizontal alignment with the table for the next upper sheet, a leer, and a plurality of superposed conveyors in the leer, for individually carrying the sheets therethrough.

2. In an apparatus for simultaneously producing a plurality of sheets of glass, a horizontal leer, a series of conveyors for carrying the separate sheets in parallel horizontal planes through the leer, and a reticular member positioned between each pair of conveyors for protecting the lower sheets from :talling material.

3. In an apparatus for simultaneously drawing a plurality of sheets of glass, a receptacle` containing a mass of'molten glass, a plurality of staggered draw tables arranged one above the other and in spaced relation, a bending roll for each draw table and over each of which a sheet drawn from the molten glass is deiiected, a roller above each draw table and the sheet carried thereby for holding the sheet in engagement with the table, the roller for the lowermost sheet being positioned in substantial horizontal alignment with the table for the next upper sheet, ak leer, and a plurality of superposed conveyors in the leer for individually carrying the sheets therethrough.

4;. In an apparatus for simultaneously drawing a plurality of sheets of glass, a receptacle containing a mass of molten glass, a plurality of staggered draw tables arranged one above the other and in spaced relation, a bending roll for each draw table and over each of which a sheet drawn from the molten glass is deflectecha roller above each draw table and the sheet carried thereby for holding the sheet in engagement with the table, the roller for the lowermost sheet being positioned in substantial horizontal alignment with the table for the next upper sheet, a leer, a plurality of superposed conveyors in the leer for individually carrying the sheets therethrough, and means positioned between each pair of conveyors for protecting the lower sheets from falling material.

5. In an apparatus for simultaneously producing a plurality of sheets of glass, a horizontal leer, a series of conveyors 'for carrying the separate sheets in parallel horizontal planes through the leer, and means positioned etween each pair of conveyors within the leer for protecting the lovver sheets from falling material while at the same time allowing the passage of air currents therethrough whereby to maintain even temperature conditions around the sheets.

6. In an apparatus for simultaneously producing a plurality of sheets of glass, a horizontal leer, a series of conveyors for carrying the separate sheets in parallel horizontal planes through the leer, and perforated means positioned between each pair of conveyors for protecting the lower sheets from falling material.

Signed at Toledo, in the county of Lucas and State of Ohio, this 23d day of January, 1924.

CLIFFGRD A. ROVVLEY. 

